Catalytic conversion of hydrocarbons



Nov. 21, 1944. c. L. THOMAS CATALYTIC CONVERSION OF HYDROOARBONS Filed Sept. 13, 1941 Patented Nov. 21,1944

w cA'rALYTIc co y 5r-HYDRO e .Charles llgfTho a :corporation of Del mas, C Universal `Oil. Product T oFF-icc NVERsIoN oF CARBONS n t Applicationfseptember 13,19411g'1Serial N o. 410,760

y t t y t 2 Claims. f.V This isla: continuation-impart of my co-pendl' .--ingapplicationuSerial No^."f279;688,.led1:June 17, y ff"1939;\ lThisinvention -relates toa process: fcrthe-` catlalyti cracking" ofpetroleum-w fractions l boiling abovel the range of .gasoline and more "particul larlyipetroleumli distillatesA which: are :vaporizable ifwithoutfsubstantial'ldecompositionbf f More speciiically-*the iinventions concernsthe conversion ofx hydrolczuarbons` byVr means of cracking l catalysts heir=reaction of producing desirable'sgas'olineAandfgaseous products from heavier lhydroc'zarbcm` distillates.` Thecatalysts used -inf-thelpresent invention in.. clude such types of-cracking'catalysts ast-hose produced-by the chemicalftreatment ofinatural occurring "substances such as clays and the synrtlieqtic gel 'catalysts dprepared bye` compositing chemically precipitated andA -puried silicaf with 3 alumina, zirconia,` thoria,` or various combinations ofijsilica with Pthese threefoxidesf These `syni theticf masses are-preparedby various-methods -gsuch as-*mixing of thegseparately'preparedconstituents or by `their coprecipitationf? l'I'l'ief` alkali ions presentl arefremoved` by washing as `their presence decreases A"the stability ofthe`1catalyst when subjected to elevated temperatures. The "ratio ofgthef-`components of these lcatalysts may beconsiderab1yvariedfalthough:themajor prog t portionsfofthe'composite is made upof silicawith f the minor proportion ofaluminafwith or Without 4Q-zirconia andthoria. t)The catalysts? arefused in j 1 the `form of sized particles `or`-forme`d shapes such uas produced bycompressionhor extrusionlmethf oldsljA `"Ihefformecl particlesf aftendrying are *calzt ined attemperatures abovey 800? F-.'prior to beupon th exactmethodofpreparation Vand the lcompositionusted.`

,-the.hydrocarbons,under cracking `conditions of temperature. and pressure `become contaminated with carbonaceous deposits' whichlmustbe re-` ;:moyedftorestorewthe activity of the catalyst. This reactivation is carried out by contacting the catalyst with an oxygen containing gas at elevated temperatures whereby the carbonaceous deposit on the catalyst is removed. The temperatures at which the reactivation is carried out are usually somewhat above 900 F. and in practice does not usually exceed I300-1400" F.` The activity ofthe catalyst varies greatly depending upon `the carbonaceous material deposited on it the freshly reactivated catalyst possessing a high .Tliacatalysts when subjected to contact with v degree oftA activity,` this activity ldecreasing astthe 'f length offthesprocess periodincreases.

y tThe-,rsusceptibility ofthe Yhighlfboilingahydrof 1 carbons to cracking `in l the presence olf-ta' catalyst 5:1 varies greatlyl with the :hydrocarbon typewfthe if olefins vprobably being Y the l :most isusceptible in l f lcracking fWhilew-'the aromatic.y hydrocarbons are 'fvery refractoryx'` :When .a complex materialsuch asafgas oil-is subjected tocontact with the,crack- Ving Y,catalyst the r; substances most -f susceptible to A --=crackingzare;y or course;` convertedtoiagreater ff: extent-V leaving ,fa recycle l fraction which :is much c less susceptible to frfurther-fprocessing than the originalxchargingstock, l l 'e Inn the'vprocessV of--m l z :charging ylstock isl f co Vzz'whiclrfliasf'previousl of :ail recycle -fraction and whichV isi consequently less effective than a freshly regenerated catalyst. Thai-temperature iused in thefcracking foffthe virin; oil :varies from'fabout I9 using afl-pressure which is mildlysuperatmospheric;` lTherecycle-stockfobtained 'inthe process is @cracked bylmeans .of a'freshlyfregeneratedfcatt alyst-` using "a temperature withinl gthei ,fapproxi- 1-1 materlimits L0ff`600e900 F. Theifpressureeused in cra-cking the 'recyclefstockzmay beasemuch` as c -gasolineffrmed in l the r-cracking of :the frecycle stock uhas a lowxbrominewnumber and aqrather `5 high lsusceptibility to ftherincrease of octane enumiberlzwith Athe `addition fof tetraethylfleadl. f In onespeciclembodimentithe'presentinvention -comprises'a process for catalytically;'cracky invention :the ,virgin ing hydrocarbon distillates to:k produce: fsubstanvtialr yields of gasoline Whichfjcomprises: t lcontacting `such'fclistillates under yconditions adequate to effectsubstantial conversion thereofwithagranular catalyst contained in a primary Lchamber'and 40` previouslyused to convert intermediatefrecycle conversion products to separate normally gaseous t, `-lzaroducts, 'gasoline and said intermediate recycle stocks, contacting `said recycle stocks` with a 445 freshly reactivated granular catalyst in a second- #vary chamben under conditionsfadequat to produce 'aA gasoline" with la low fdegree of unsaturation, fractionating the' products from the secondary chamber `to recover the gasoline and the remaining portion of insufficiently converted higher boiling hydrocarbons.'

The accompanying drawing illustrates dia` y one embodiment of the invention. y

grammaticall The drawin attempt ha g has not been made to scale and no ,ntactedf 'yvvith `the-catalyst ylI beenvused inlfithe-Icracking 00- to" 1100@ Et; 'while `stocks hereinafter described;fractionating the` s been made to proportionate the vari- "f the" carbonaceous lmaterials valve's lare. switched so.`

ous part of the equipment exactly. The invention should not be construed as limited to the exact apparatus or conditions given herein.

Referring to the drawing, the original petroleum fraction enters the system through line I, valve 2, pump 3, valve 4 and coil 5 which is disposed. in. ilirnaceii,` l,The oilis heated to ,ha temperature Whiclrmay vary from about`900 toabout 1100 F. and leaves the furnace `through line 1, valve 8 and then passes through line 9, into catalytic converter II. The reaction products pass through line I2, valve I3 to` fractionato'r I4. and valve I6 to suitable stabilizers and condenser-s, etc. which are not shown-Y4 sufficiently converted oil may be the system by way of line IJ, valve I8 to storage. verted oil which is recycled for further ,conver-l sion is passed through line I9, valve 20, pump 2 I, 'ff-valve 22`to coil 23vvhich-'is 4disposedinfurnace 24.

*which containslvalve IB to'line I9 and then by previously-described routes to coil-23 and thecatalytic cracking step. At the ysame time aportion of the oil isyvithdrlawn from the system through eline I1 'and' valve 18;" In` coil l23 the'frecycle oil l isheated to-a temperature" whichima'y ,vary frorh :'aboutGOOfto about 900i" F.' While utilizing pressres X which may vary from ipheric to several hundred pounds per squareinch terpreted as being Another portion of theinsufliciently con-`v A l, A Pennsylvania gas oil of 37.3 A. P. I. gravity mildly superatmosand valves I3 and 46. Thus each passes through the incracking of recycle line I2 and 45 converter in a single cycle dividual steps of regeneration,

oil and cracking of the original fraction in the order named.

Since the recycle oil and original fraction are heated inzseparate furnaces thetemperature at y ,which they are converted may )be controlled as desired.

The various heat exchanges, coolers, condensers, stabilizers, gas circulation and equipment which are necessary to the operation of the f processbut are not a specific feature of the in- The gasoline and gas pass through-'line I5 i fV-f r`ve'rition are not shown in the interest of simplify- `ing the drawing.

Thedollovvng example is ar'z'r'ili'cabilityA ofthe process and should not be inlimited to the exact Iconditions given'therein.

Was cracked according to the above described inventionf. The'l catalyst used :Was: a synthetic; silica masscon'taining aminor proportion of aluminum fraction vmay be withdrawn and zirconium. The temperatures used for crackl vingtheoriginal petroleum ,fraction Was975 F.

*and thatfor the vrecyclestock Was1800 F. Thefreby means ofl a mixture of f ',.uair'and flue gas having anoxygenfconcentration y Vsof .about 3- percent. tivation does .not

.400 end pointgasoline based-,on theoriginal The temperature offv reacexceed 1300i F. The .yield of charge and includingfthat obtained bythepQIy- The heatedrecycle oil-.passes` ithroughfliney 25,

together with :the oil I 1 kdeposited on thezcatalyst; the'sp'entlregenerating of :regeneration `for converterg34 ;is complete,` the Ztion fr'om'lin'e 1 is conducted into converterA 29 I by means ofline 31; valve 38'.

' f `line `254 is passed intoY catalytic converter 34 by '.means4 of line 39 andvalve 4,0;- The-regeneration gasesiromlline 32' are passed into catalytic cony gases being removed I i'ltlirough line35'v and valve 36.v Whenthe period that lthe petroleum vfrac- 'I'he recycle oil from meriZatiOnof-the C3 and-.C4

oleflns from fthe process gases amountsto about y84-.percentof-theoriginal charge. V4'I'eheloctane number of thisgasoline is about V'79 CFR -motor method-v -1 Iclaimasrriy'invention:i 1 f1. Theprocess `.of catalytically cracking, hydro-V generated catalyst, employing said catalyst to mpromote theicracking `of saidrecycle ovilr-untilits 34f'therein oxidizing fue heavy conversion y'products-on the .atalyiig and thereafter employing activity is reduced' by the deposition of deleterious the l partially',spentcatalyst -to promote the cracking of a virgin .oil at a :temperature higher than that employed `for cracking said recycle oil.,A Y 2. Ihe hydrocarbon conversion process.which y comprises cracking virgin charging oil inthepres- A -ence of Apartiallyspent cracking `catalyst derived I as hereinafter described, `fractionating'resulting i verterll by means of line 4I,-valve 42; The spent regenerating gases-leave converter'l I through line 43 and valve 44. Theconversion products'from converter 29 and converter 34 are gathered in line `I 2 from lines130 and! 45 Simultaneously'after regeneration ofthe catalyst I I is complete. the original .petroleum .f

in ,converter 1- fractionI is fsyvitchedinto converter- 3 i of line 4.1- alve IQ-.iflhereeyele ymeellslofiline ,era 10e .ease

means .eil-1e essedint@ ndva' e' 50 and .32` ter.,con

and valves 3l and 4S. alyst, and thereafter employing resulting partially cracked vapors. to separate` selected low boiling kfractions therefrom andA obtain recycle oil` comprising higher boiling components thereof, regenerating catalyst Vwhich has been employed in the `cracking ot said virgin oil, crackingfsaid recycle oil in thepresence ofthe regenerated' catspent catalyst.

from the recycle oil cracking step,

lwithout intermediate regenera leutenpromote J- said virgin oilcracking operati, eprocess be` g`'f` e'd'b'y ofaihigher given to illustrate-the 

